The invention relates to pharmaceutically active macrolides. Halichondrin B is a potent anticancer agent originally isolated from the marine sponge Halichondria okadai, and subsequently found in Axinella sp., Phakellia carteri, and Lissondendryx sp.
A total synthesis of Halichondrin B was published in 1992 (Aicher, T. D. et al.,J. Am. Chem. Soc. 114:3162-3164). Halichondrin B has demonstrated in vitro inhibition of tubulin polymerization, microtubule assembly, betaS-tubulin crosslinking, GTP and vinblastine binding to tubulin, and tubulin-dependent GTP hydrolysis and has shown in vitro and in vivo anti-cancer properties.
The invention provides halichondrin analogs having pharmaceutical activity, such as anticancer or antimitotic (mitosis-blocking) activity. These compounds are substantially smaller than halichondrin B. The invention features a compound having the formula (I): 
In formula (I), A is a C1-6 saturated or C2-6 unsaturated hydrocarbon skeleton, the skeleton being unsubstituted or having between 1 and 13 substituents, preferably between 1 and 10 substituents, e.g., at least one substituent selected from cyano, halo, azido, Q1, and oxo. Each Q1 is independently selected from OR1, SR1, SO2R1, OSO2R1, NR2R1, NR2(CO)R1, NR2(CO)(CO)R1, NR4(CO)NR2R1, NR2(CO)OR1, (CO)OR1, O(CO)R1, (CO)NR2R1, and O(CO)NR2R1. The number of substituents can be, for example, between 1 and 6, 1 and 8, 2 and 5, or 1 and 4. Throughout the disclosure, numerical ranges are understood to be inclusive.
Each of R1, R2, R4, R5, and R6 is independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 aminoalkyl, C6-10 aryl, C6-10 haloaryl (e.g., p-fluorophenyl or p-chlorophenyl), C6-10 hydroxyaryl, C1-4 alkoxy-C6 aryl (e.g., p-methoxyphenyl, 3,4,5-trimethoxyphenyl, p-ethoxyphenyl, or 3,5-diethoxyphenyl), C6-10 aryl-C1-6 alkyl (e.g., benzyl or phenethyl), C1-6 alkyl-C6-10 aryl, C6-10 haloaryl-C6-10 alkyl, C1-6 alkyl-C6-10 haloaryl, (C1-3 alkoxy-C6 aryl)-C1-3 alkyl, C2-9 heterocyclic radical, C2-9 heterocyclic radical-C1-6 alkyl, C2-9 heteroaryl, and C2-9 heteroaryl-C1-6 alkyl. There may be more than one R1, for example, if A is substituted with two different alkoxy (OR1) groups such as butoxy and 2-aminoethyoxy.
Examples of A include 2,3-dihydroxypropyl, 2-hydroxyethyl, 3-hydroxy-4-perfluorobutyl, 2,4,5-trihydroxypentyl, 3-amino-2-hydroxypropyl, 1,2-dihydroxyethyl, 2,3-dihyroxy-4-perflurobutyl, 3-cyano-2-hydroxypropyl, 2-amino-1-hydroxy ethyl, 3-azido-2-hydroxypropyl, 3,3-difluoro-2,4-dihydroxybutyl, 2,4-dihydroxybutyl, 2-hydroxy-2(p-fluorophenyl)-ethyl, xe2x80x94CH2(CO)(substituted or unsubstituted aryl), xe2x80x94CH2(CO)(alkyl or substituted alkyl, such as haloalkyl or hydroxyalkyl) and 3,3-difluoro-2-hydroxypent-4-enyl.
Examples of Q1 include xe2x80x94NH(CO)(CO)-(heterocyclic radical or heteroaryl), xe2x80x94OSO2-(aryl or substituted aryl), xe2x80x94O(CO)NH-(aryl or substituted aryl), aminoalkyl, hydroxyalkyl, xe2x80x94NH(CO)(CO)-(aryl or substituted aryl), xe2x80x94NH(CO)(alkyl)(heteroaryl or heterocyclic radical), O(substituted or unsubstituted alkyl)(substituted or unsubstituted aryl), and xe2x80x94NH(CO)(alkyl)(aryl or substituted aryl).
Each of D and Dxe2x80x2 is independently selected from R3 and OR3, wherein R3 is H, C1-3 alkyl, or C1-3 haloalkyl. Examples of D and Dxe2x80x2 are methoxy, methyl, ethoxy, and ethyl. In some embodiments, one of D and Dxe2x80x2 is H.
The value for n is 1 or preferably 0, thereby forming either a six-membered or five-membered ring. This ring can be unsubstituted or substituted, e.g., where E is R5 or OR5, and can be a heterocyclic radical or a cycloalkyl, e.g. where G is S, CH2, NR6, or preferably O.
Each of J and Jxe2x80x2 is independently H, C1-6 alkoxy, or C1-6 alkyl; or J and Jxe2x80x2 taken together are xe2x95x90CH2 or xe2x80x94O-(straight or branched C1-5 alkylene or alkylidene)-O-, such as exocyclic methylidene, isopropylidene, methylene, or ethylene. Q is C1-3 alkyl, and is preferably methyl. T is ethylene or ethenylene, optionally substituted with (CO)OR7, where R7 is H or C1-6 alkyl. Each of U and Uxe2x80x2 is independently H, C1-6 alkoxy, or C1-6 alkyl; or U and Uxe2x80x2 taken together are xe2x95x90CH2 or xe2x80x94O-(straight or branched C1-5 alkylene or alkylidene)-O-. X is H or C1-6 alkoxy. Each of Y and Yxe2x80x2 is independently H or C1-6 alkoxy; or Y and Yxe2x80x2 taken together are xe2x95x90O, xe2x95x90CH2, or (straight or branched C1-5 alkylene or alkylidene)-O-. Each of Z and Zxe2x80x2 is independently H or C1-6 alkoxy; or Z and Zxe2x80x2 taken together are xe2x95x90O, xe2x95x90CH2, or -(straight or branched C1-5 alkylene or alkylidene)-O-.
The invention features compounds of sufficient stability to be suitable for pharmaceutical development. The invention also features pharmaceutically acceptable salts of disclosed compounds, disclosed novel synthetic intermediates, pharmaceutical compositions containing one or more disclosed compounds, methods of making the disclosed compounds or intermediates, and methods of using the disclosed compounds or compositions. Methods of use include methods for reversibly or irreversibly inhibiting mitosis in a cell, and for inhibiting cancer or tumor growth in vitro, in vivo, or in a patient. The invention also features methods for identifying an anti-mitotic or anti-cancer agent, such as a reversible or, preferably, an irreversible agent.